Magnetic field formation device, power supplying device, power receiving device, power receiving/supplying device, portable device, coil device, and magnetic field formation method

ABSTRACT

A variable magnetic field in which a power-supplying coil and a power supplying resonator exist is generated only by the power-supplying coil. Power-supplying coils and each of which generates a variable magnetic field due to the supply of a variable current via a first current path on one coil end a side and a second current path on the other coil end side; resonance capacitors which are provided on the first current path and the second current path; and a power-supplying coil short-circuit mechanism which is able to cause at least one of the power-supplying coils and to function as a power supplying resonator by allowing the end portions and of the first current path and the second current path to short-circuit with each other are provided.

TECHNICAL FIELD

The present invention relate to a magnetic field formation device forming a magnetic field at a predetermined region, a power-supplying device, a power-receiving device, a power receiving/supplying device, a mobile device, a coil device, and a magnetic field formation method.

BACKGROUND

A structure of wireless power transmission from a power feeding coil to a power-receiving coil by electromagnetic induction or magnetic field resonance has been proposed (e.g., Patent Literature 1 and Patent Literature 2).

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Unexamined Patent Publication No. 2015-144508

[Patent Literature 2] Japanese Unexamined Patent Publication No. 2013-240260

SUMMARY OF INVENTION Technical Problem

In regard to the above, the roles and functions of the power feeding coil and the power-receiving coil have been fixed, and there has been no structures focusing on the roles and functions of the coils.

An object of the present invention is to provide a magnetic field formation device, a power-supplying device, a power-receiving device, a power receiving/supplying device, a mobile device, a coil device, and a magnetic field formation method, which form a magnetic field with focus on the roles and functions of the coils.

Solution to Problem

The present invention relates to a magnetic field formation device which includes: power-supplying coils each of which generates a variable magnetic field as a variable current is supplied to each of the power-supplying coils via a first current path on one coil end side and a second current path on the other coil end side; a resonance capacitor which is provided on at least one of the first current path and the second current path; and a power-supplying coil short-circuit mechanism which is capable of causing at least one of the power-supplying coils to function as a power supplying resonator by short-circuiting end portions of the first current path and the second current path.

According to the arrangement above, when the end portions of the first current path and the second current path of at least one of the power-supplying coils are short-circuited by the power-supplying coil short-circuit mechanism, this power-supplying coil functions as a power supplying resonator which resonates with a variable magnetic field generated by the other power-supplying coil to which a variable current is supplied. In this way, a variable magnetic field in which the power-supplying coil and the power supplying resonator exist is generated only by the power-supplying coils.

The magnetic field formation device of the present invention may generate a variable magnetic field at a predetermined region, all of the power-supplying coils may be disposed so that coil surfaces oppose the predetermined region, and at least one of the power-supplying coils may be disposed to have a coil surface direction which intersects with coil surface directions of the other power-supplying coils. The magnetic field formation device of the present invention may generate a variable magnetic field at a predetermined region, all of the power-supplying coils may be disposed so that coil surfaces oppose the predetermined region, and at least one of the power-supplying coils may be disposed to have a coil surface direction which is parallel to coil surface directions of the other power-supplying coils.

According to the arrangements above, a variable magnetic field in which the power-supplying coil and the power supplying resonator exist is generated at the predetermined region only by the power-supplying coils. According to the arrangements above, furthermore, a variable magnetic field with high magnetic field strength or low magnetic field strength can be formed at a part of the predetermined region by the variable magnetic field of the power-supplying coil and the variable magnetic field of the power-supplying coil functioning as a power supplying resonator, based on the positional relation between the power-supplying coils. This is achieved by adjusting the angles, locations, etc. of the coil surfaces of the power-supplying coils.

The magnetic field formation device of the present invention may further include a current output controller which is configured to output a variable current to one of output targets which are at least one of and not all of the power-supplying coils and to be capable of switching the output target to which the variable current is output.

According to this arrangement, it is possible to change the distribution of the magnetic field strength of a variable magnetic field by sending a magnetic field from each power-supplying coil to the power-supplying coil functioning as the power supplying resonator at a different angle. Furthermore, as the power supplying resonator (power-supplying coil) resonates on account of the variable magnetic field of each of the power-supplying coils, the magnetic field strength of the variable magnetic field at the predetermined region is enhanced.

The magnetic field formation device of the present invention may be arranged such that the current output controller executes a stop process of not outputting the variable current to any of the power-supplying coils, with a predetermined combination of a timing and a duration.

With this arrangement, it is possible to easily generate a variable magnetic field with predetermined magnetic field strength in consideration of heat generation and power consumption, by adjusting the timing and duration of the stop process.

The present invention relates to a power-supplying device including one of the above-described magnetic field formation devices.

The present invention relates to a power-receiving device including a power-receiving mechanism which is configured to receive power by a variable magnetic field generated at a predetermined region by anyone of the above-described magnetic field formation devices.

The power-receiving device of the present invention may include: a power-receiving mechanism configured to receive power by the variable magnetic field; and a high-capacitance capacitor which has a capacity of being charged by a current received by the power-receiving mechanism and discharging at least at a minimum operating voltage of an electric part on a subsequent stage while an output target of the variable current by the current output controller is being switched.

According to the arrangement above, even when an induced current cannot be easily obtained from the power-receiving mechanism on account of the switching of the output target of the variable current, the electric part is stably driven because the high-capacitance capacitor performs the discharge at least at the minimum operating voltage of the electric part.

The high-capacitance capacitor of the power-receiving device of the present invention may have a capacity of discharging at least at the minimum operating voltage of the electric part on the subsequent stage during a stop process in which the current output controller does not supply the variable current to any of the power-supplying coil.

According to this arrangement, in addition to the period during which the switching of the output target of the variable current is being performed by the current output controller, even when an induced current cannot be obtained from the power-receiving mechanism due to the stop process for the power-supplying coil and the power supplying resonator, the electric part is stably driven as the high-capacitance capacitor performs the discharge at least at the minimum operating voltage of the electric part.

The present invention relates to a power receiving/supplying device including: a power-supplying device including any one of the above-described magnetic field formation devices; and a power-receiving device including a power-receiving mechanism which is configured to receive power by the variable magnetic field generated by the power-supplying device.

The present invention relates to a mobile device including a power-receiving mechanism which is configured to receive power by a variable magnetic field generated at a predetermined region by any one of the above-described magnetic field formation devices.

The present invention relates to a coil device including: a coil; a variable current supplying mechanism configured to supply a variable current to the coil via a first current path on one coil end side and a second current path on the other coil end side; a resonance capacitor which is provided on at least one of the first current path and the second current path, in a connection state which is a least one of connection in series with the coil and connection parallel to the coil; and a coil short-circuit mechanism which is capable of forming a power supplying resonator by short-circuiting end portions of the first current path and the second current path.

According to this arrangement, the coil is switchable between a coil generating a variable magnetic field and a power supplying resonator resonating with a variable magnetic field.

The present invention relates to a magnetic field formation method including the steps of: generating a variable magnetic field by supplying a variable current via a first current path on one coil end side and a second current path on the other coil end side; and switching at least one of power-supplying coils to a power supplying resonator by short-circuiting end portions of the first current path and the second current path, a resonance capacitor being provided on at least one of the first current path and the second current path of the power-supplying coils.

According to the arrangement above, when the end portions of the first current path and the second current path of at least one of the power-supplying coils are short-circuited, this power-supplying coil functions as a power supplying resonator which resonates with a variable magnetic field generated by the other power-supplying coil to which a variable current is supplied. In this way, a variable magnetic field in which the power-supplying coil and the power supplying resonator exist is generated only by the power-supplying coils.

Advantageous Effects

According to the present invention, a variable magnetic field in which the power-supplying coil and the power supplying resonator exist is generated only by the power-supplying coils.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic explanatory diagram of a magnetic field formation device in a front view.

FIG. 2A illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 2B illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 2C illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 2D illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 2E illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 2F illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 2G illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 2H illustrates a connection relation between a power-supplying coil and a resonance capacitor.

FIG. 3 is a schematic explanatory diagram of a magnetic field formation device in a front view.

FIG. 4A is a schematic explanatory diagram of a magnetic field formation device in a front view.

FIG. 4B is a schematic explanatory diagram of a magnetic field formation device in a front view.

FIG. 5 is a schematic explanatory diagram of a magnetic field formation device in a front view.

FIG. 6 is a schematic explanatory diagram of a magnetic field formation device in a plan view.

FIG. 7 is a schematic explanatory diagram of a magnetic field formation device in a plan view.

FIG. 8 is a schematic explanatory diagram of a magnetic field formation device in a front view.

FIG. 9 is a schematic explanatory diagram of a magnetic field formation device in a front view.

FIG. 10 is a schematic explanatory diagram of a magnetic field formation device in a plan view.

FIG. 11 is a block diagram of a magnetic field formation device.

FIG. 12 illustrates operations of a power-supplying coil short-circuit mechanism.

FIG. 13 is a block diagram of a magnetic field formation device.

FIG. 14 is an explanatory diagram of operations of a current path switcher.

FIG. 15 is a block diagram of a power receiving/supplying device.

FIG. 16 is a block diagram of a driving device.

FIG. 17 is a block diagram of a driving device.

FIG. 18 is a block diagram of a driving device.

DESCRIPTION OF EMBODIMENTS

The following will describe an embodiment of the present invention with reference to drawings. (Magnetic Field Formation Device: Overview)

As shown in FIG. 1, a magnetic field formation device 101 includes: power-supplying coils 111 and 112 each of which generates a variable magnetic field due to the supply of a variable current via a first current path 141 on one coil end 141 a side and a second current path 142 on the other coil end 142 a side; resonance capacitors 151 and 151 which are provided on the first current path 141 and the second current path 142; and a power-supplying coil short-circuit mechanism 1313 which is able to cause at least one of the power-supplying coils 111 and 112 to function as a power supplying resonator by allowing the end portions 141 a and 142 a of the first current path 141 and the second current path 142 to short-circuit with each other.

Each resonance capacitor 151 is provided on the first current path 141 or the second current path 142 to be in series with or parallel to one of the power-supplying coils 111 and 112. Specific examples are shown in FIG. 2A to FIG. 2H.

FIG. 2A shows a state in which a resonance capacitor 151 is connected in series at a part of the first current path 141, which is between the end portion 141 a of the first current path 141 and the coil end of the power-supplying coil 111. FIG. 2B shows a state in which two resonance capacitors 151 are connected in series on the first current path 141. FIG. 2C shows a state in which resonance capacitors 151 are connected in series on the first current path 141 and the second current path 142, respectively.

FIG. 2D shows a state in which two resonance capacitors 151 provided in a parallel manner are connected in series on the first current path 141. FIG. 2E shows a state in which two resonance capacitors 151 provided in a parallel manner are connected in series on the first current path 141 whereas a resonance capacitor 151 is connected in series on the second current path 142. FIG. 2F shows a state in which two resonance capacitors 151 provided in a parallel manner are connected in series on the first current path 141 whereas two resonance capacitors 151 provided in a parallel manner are connected in series on the second current path 142.

FIG. 2G shows a state in which a resonance capacitor 151 is connected to the first current path 141 and the second current path 142 to be parallel to the power-supplying coil 111. FIG. 2H shows a state in which a resonance capacitor 151 is connected to the first current path 141 and the second current path 142 to be parallel to the power-supplying coil 111, and a resonance capacitor 151 is connected in series on the first current path 141. The connection states shown in FIG. 2A to FIG. 2H are examples, and the number, the series connection, the parallel connection, and the locations of the resonance capacitors 151 may be suitably selected and combined.

As shown in FIG. 1, the power-supplying coil short-circuit mechanism 1313 is provided in an oscillation controller 131 together with an oscillator 1312. The oscillation controller 131 will be detailed later. With this arrangement, the magnetic field formation device 101 realizes a magnetic field formation method of switching at least one of the power-supplying coils 111 and 112 generating a variable magnetic field with the supply of a variable current to a power supplying resonator by short-circuiting the end portions 141 a and 142 a of the first current path 141 and the second current path 142 with each other.

In the magnetic field formation device 101 structured as described above, when the end portions 141 a and 142 a of the first current path 141 and the second current path 142 of at least one of the power-supplying coils 111 and 112 are short-circuited by the power-supplying coil short-circuit mechanism 1313, this power-supplying coil 111 (112) functions as a power supplying resonator which resonates with a variable magnetic field generated by the other power-supplying coil 112 (111) to which a variable current is supplied. In this way, a variable magnetic field in which the power-supplying coil 111 (112) and the power supplying resonator 112 (111) exist is generated only by the power-supplying coils 111 and 112.

The magnetic field formation device 101 may be formed by at lest one coil device which is configured to switch the power-supplying coil 112 (111) between a coil for electromagnetic induction and a coil for magnetic field resonance by whether to short-circuit the end portions 141 a and 142 a of the first and second current paths 141 and 142 by the coil short-circuit mechanism 1313.

To specifically describe the coil device, the coil device includes a coil, a resonance capacitor which is provided on at least one of the first current path on one coil end side and the second current path on the other coil end side of the coil, and a coil short-circuit mechanism which is capable of causing the coil to function as a resonator by causing the end portions of the first current path and the second current path of the coil to be short-circuited. This coil may be a power-supplying coil or a power-receiving coil. According to this arrangement, the coil device is able to switch the coil between a coil for electromagnetic induction and a coil for magnetic field resonance by whether to short-circuit the end portions of the first and second current paths by the coil short-circuit mechanism.

Furthermore, the coil device may include a current output unit which supplies a variable current via the first current path and the second current path. According to this arrangement, the coil is switchable between a power-supplying coil for electromagnetic induction and a power-supplying resonance coil for magnetic field resonance by whether to short-circuit the end portions of the first and second current paths by the coil short-circuit mechanism, even in a state i which the operation f the current output unit outputting a variable current is maintained, i.e., without stopping an output from the current output unit.

All of the power-supplying coils 111 and 112 are provided so that coil surfaces 111 a and 112 a oppose the predetermined region A, and at least one of the power-supplying coils 111 and 112 is provided to have a coil surface direction intersecting with the coil surface direction of the other one of the power-supplying coils 111 and 112. The coil surface direction is a direction in parallel to a coil surface.

Alternatively, as shown in FIG. 3, at least one of the power-supplying coils 111 and 112 may be provided to have a coil surface direction parallel to the coil surface direction of the other one of the power-supplying coils 111 and 112. In this case, the power-supplying coils 111 and 112 may be arranged so that the coil surfaces 111 a and 112 a having the coil surface directions parallel to each other sandwich at least a part of the predetermined region A. Furthermore, in the case above, the power-supplying coils 111 and 112 may be disposed to at least partially overlap each other when one of the coil surfaces 111 a and 112 a having the coil surface directions parallel to each other is projected onto the other coil surface in the direction along the coil axis.

Alternatively, the power-supplying coils 111 and 112 may be disposed so that the coil surface 111 a or 112 a of at least one of the power-supplying coils 111 and 112 and the coil surface 111 a or 112 a of the other one of the power-supplying coils 111 and 112 are not on the same plane.

In the magnetic field formation device 101 structured as above, a variable magnetic field with high magnetic field strength or low magnetic field strength can be formed at a part of the predetermined region A by the variable magnetic field of the power-supplying coil 111 (112) and the variable magnetic field of the power-supplying coil 112 (111) functioning as a power supplying resonator, based on the positional relation between the power-supplying coils 111 and 112. This is achieved by adjusting the angles, locations, etc. of the coil surfaces 111 a and 112 a of the power-supplying coils 111 and 112. In this way, a magnetic field which is partially a variable magnetic field with high or low magnetic field strength can be formed at the predetermined region A.

Furthermore, in the magnetic field formation device 101, by the power-supplying coil 111 (112) functioning as a power supplying resonator and the other power-supplying coil 112 (111), a magnetic field area which enables power transmission by magnetic field resonance and a magnetic field area which enables power transmission by electromagnetic induction can be provided in the predetermined region. In other words, in the magnetic field formation device 101, because the distance in which the magnetic field resonance is possible is longer than the distance in which the electromagnetic induction is possible, a magnetic field area in which power transmission is mainly conducted by the electromagnetic induction in short distances from the power-supplying coil 111 (112) and a magnetic field area in which power transmission is conducted mainly by the magnetic field resonance in long distances can be provided in the predetermined region. On this account, the magnetic field formation device 101 is suitable for power transmission in a large-sized predetermined region.

The “variable magnetic field” indicates one of (1) a magnetic field in a state in which the direction of the magnetic lines of force alternately changes between the forward direction and the reverse direction, (2) a magnetic field in a state in which the magnetic field strength changes while the direction of the magnetic lines of force is the forward direction, (3) a magnetic field in a state in which the magnetic field strength changes while the direction of the magnetic lines of force is the reverse direction, and (4) a magnetic field in a state in which two or more of the states (1) to (3) are combined.

The “predetermined region A” may be of any size or shape. The predetermined region A is a reverse frustum in shape, in which the lower face is smaller than the upper face. The reverse frustum shape may be a reverse circular frustum shape, a reverse square frustum shape, or an N-sided frustum shape. While in the present embodiment the predetermined region A is reverse frustum in shape, the disclosure is not limited to this arrangement. In other words, as shown in FIG. 4A, the inclination angle of at least one side face may be different from the inclination angles of the remaining side faces in the predetermined region A, or the predetermined region A may be a frustum in which the lower face is larger in diameter than the upper face as shown in FIG. 4B. The predetermined region A may be sized and shaped to correspond to an object provided in the variable magnetic field, or may be sized and shaped to correspond to a receiving space such as a container, a housing box, a room, etc. in which the object is housed. The “predetermined region A: may be a hexahedron such as a rectangular parallelepiped body, a cube, or a triangular prism.

An example of the “object” is a driving device including a power-receiving device to which power is supplied by a variable magnetic field. The driving device encompasses all types of devices driven by electric power. Examples are a mobile device, a home electric appliance, and an automobile.

While in the present embodiment the magnetic field formation device 101 includes only the power-supplying coils 111 and 112, the magnetic field formation device 101 may include at least one power supplying resonator. The “power supplying resonator” is of a spiral type, a solenoid type, or a loop type, for example, and is a coil in which the ends of the coil are directly connected (short-circuited) to each other or indirectly connected (short-circuited) to each other by a GND or the like. When an induced current is supplied, the power supplying resonator generates a variable magnetic field at the predetermined region A opposing the coil surface and generates a variable magnetic field at a region opposite to the predetermined region A over the power supplying resonator.

While in the present embodiment one oscillation controller 131 is provided for plural power-supplying coils 111 and 112, the disclosure is not limited to this arrangement and an oscillation controller 131 may be provided for each of power-supplying coils 111 and 112. In other words, the magnetic field formation device 101 may be formed by combining a coil device including a coil (power-supplying coil 111), a variable current supply mechanism (oscillator 1312) configured to supply a variable current to the coil, and a coil short-circuit mechanism (power-supplying coil short-circuit mechanism 1313) capable of causing the end portions 141 a and 142 a of the first current path 141 and the second current path 142 to be short-circuited. According to this arrangement, because the coil of each coil device is switchable between a coil generating a variable magnetic field and a power supplying resonator resonating with a variable magnetic field, the control for magnetic field formation may be easily done.

(Magnetic Field Formation Device: Power-Supplying Coil)

The “power-supplying coils 111 and 112” are of a spiral type, a solenoid type, or a loop type, for example, and are coils which generate an induction current at a power-supplying coil 111 or 112 which functions as a power supplying resonator on account of an externally-supplied variable current. The “variable current” indicates one of (1) a current which alternately varies to the positive side and the negative side over 0 ampere, (2) a current which varies on the positive side, (3) a current which varies on the negative side, and (4) a current in a state in which two or more of the states (1) to (3) are combined.

All of the power-supplying coils 111 and 112 are provided so that coil surfaces 111 a and 112 a oppose the predetermined region, and at least one of the power-supplying coils 111 and 112 is provided to have a coil surface direction intersecting with the coil surface direction of the other one of the power-supplying coils 111 and 112. For example in case of the magnetic field formation device 101, 101A including the predetermined region A as shown in FIG. 1 and FIG. 4A, the power-supplying coils 111 and 112 are disposed along the side faces of the predetermined region A and hence the coil surface directions intersect with each other at a location below the predetermined region A. In case of the magnetic field formation device 101B including the predetermined region A as shown in FIG. 4B, the power-supplying coils 111 and 112 are disposed along the side faces of the predetermined region A and hence the coil surface directions intersect with each other at a location above the predetermined region A.

While in FIG. 1, FIG. 4A, and FIG. 4B two power-supplying coils 111 and 112 are provided for convenience of explanation, the number of the power-supplying coils is not limited to this. The number of the power-supplying coils may be variously set on condition that the number is two or more. For example, as shown in FIG. 5, three power-supplying coils 111, 112, and 115 are provided, and a coil surface 115 a of the power-supplying coil 115 is disposed to oppose the bottom surface of the predetermined region A.

Alternatively, for example, as shown in FIG. 6, when viewed from a point above the predetermined region A, three power-supplying coils 111, 112, and 113 may be provided along the respective sides of an equilateral triangle which is centered at the predetermined region A. In this case, the state of the end face cut along the X-X line in FIG. 6 corresponds to the positional relation between the power-supplying coils 111, 112, and 115 shown in FIG. 5.

Alternatively, for example, as shown in FIG. 7, when viewed from a point above the predetermined region A, four power-supplying coils 111, 112, 113, and 114 may be provided along the respective sides of a square which is centered at the predetermined region A. In this case, the state of the end face cut along the X-X line in FIG. 7 corresponds to the positional relation between the power-supplying coils 111, 112, and 115 shown in FIG. 5.

As shown in FIG. 8, the coil surfaces of the power-supplying coils 111 and 112 provided to sandwich the predetermined region A have sizes and shapes corresponding to those of the side faces of the predetermined region A. For example, the coil surfaces 111 a and 112 a of the power-supplying coils 111 and 112 may be formed to be trapezoidal to correspond to the predetermined region A having a reverse frustum shape, or to be elliptical (power-supplying coil 111A). Each of the coil surfaces of the power-supplying coils 111 and 112 may be, for example, circular, triangular, quadrangular, or polygonal in shape to correspond to the size of the predetermined region A. The shapes of the coil surfaces 111 a and 112 a of the power-supplying coils 111 and 112 may be different from each other. The coil surfaces 111 a and 112 a of the power-supplying coils 111 and 112 may be formed to correspond to a projected shape of a side face of the predetermined region A, or may be formed in accordance with factors such as the disposition of the other power-supplying coils 111, 112, and 115.

Each of the power-supplying coils 111 and 112 may be formed of plural power supplying sub coils. For example, in the power-supplying coil 111, a coil surface 111 a which is trapezoidal on the whole may be formed by gathering power supplying sub coils 1111 which are identical or different in size. Alternatively, in the power-supplying coil 111, a coil surface 111 a which is trapezoidal on the whole may be formed by gathering power supplying sub coils 1111 and power supplying sub coils 1112 which are different in shape from the power supplying sub coils 1111 and each of which is trapezoidal, for example.

The power-supplying coils 111 and 112 may be disposed so that the outer peripheries thereof partially overlap each other. With this arrangement, the magnetic field strength is easily uniformized by causing the outer peripheries of the power-supplying coils 111 and 112 with low magnetic field strength to overlap each other.

A coil surface 115 a of the power-supplying coil 115 provided below the predetermined region A is sized and shaped to correspond to the size and shape of the bottom of the predetermined region A. For example, the coil surface 115 a of the power-supplying coil 115 may be circular in shape to correspond to the size of the predetermined region A, or may have another shape. To be more specific, the coil surface 115 a may be triangular as in a power-supplying coil 115A, the coil surface 115 a may be quadrangular as in a power-supplying coil 115B, or the coil surface 115 a may have another shape such as polygonal or elliptical. The shape of the coil surface 115 a of the power-supplying coil 115 may correspond to the shape of the bottom of the predetermined region A, or may be determined in accordance with factors such as the disposition of the other power-supplying coils 111 and 112.

The number of the power-supplying coils 115 is one or more. When there are plural power-supplying coils 115, each of the power-supplying coils 115 may have a coil surface with a desired shape, as power supplying sub coils 1151 which are identical or different in size are gathered. Alternatively, a power-supplying coil 115 may be formed of an annular power supplying sub coil 1152 corresponding to the coil surface shape and power supplying sub coils 1151 provided on the inner circumferential side of the power supplying sub coil 1152. When a power-supplying coil 115 is formed by plural power supplying sub coils 1151 (1152), it is possible to finely adjust the magnetic field strength of a variable magnetic field at around the bottom portion of the predetermined region A, by each power supplying sub coil 1151 (1152).

As shown in FIG. 9 and FIG. 10, the magnetic field formation device 101 may be arranged such that plural, e.g., three power-supplying coils 111, 112, and 113 are disposed to form a flat plate. In other words, the power-supplying coils 111, 112, and 113 may be disposed so that the coil surfaces 111 a, 112 a, and 113 a of the power-supplying coils 111, 112, and 113 are on the same plane. In this case, the size and shape of the predetermined region A in the planar direction can be arbitrarily set by increasing the number of the power-supplying coils 111, 112, and 113 provided. The disposition direction may be a horizontal direction, a vertical direction, or a direction inclined with respect to the vertical direction or the horizontal direction.

(Magnetic Field Formation Device: Oscillation Controller)

As shown in FIG. 11, the magnetic field formation device 101 structured as described above includes the oscillation controller 131 (which is an example of a current output controller) connectable to an external power source PS. While a magnetic field formation device 101 including three power-supplying coils 111, 112, and 113 will be described below, the disclosure is not limited to this arrangement.

The oscillation controller 131 includes: a power-supplying coil short-circuit mechanism which causes each of the power-supplying coils 111, 112, and 113 to function as a power supplying resonator; and an output target switching mechanism which is configured to output a variable current to one of output targets which are at least one of and not all of the power-supplying coils 111, 112, and 113 and to be capable of switching the output target to which the variable current is output. The output target switching mechanism of the oscillation controller 131 is preferably arranged to repeatedly change a magnetic field state which is a combination of the direction, density, and magnitude of magnetic lines of force in a variable magnetic field. In this case, the magnetic field strength of the variable magnetic field in the predetermined region A is uniformized by repeatedly changing the magnetic field state which is a combination of the shape and density of magnetic lines of force in the variable magnetic field. With this arrangement, when, for example, the magnetic field formation device 101 is mounted on a power-supplying device, the power supply is possible without significant deterioration in the power receiving efficiency depending on the direction and position of the power-receiving device.

To be more specific, the oscillation controller 131 includes the oscillator 1312 configured to output a variable current and the power-supplying coil short-circuit mechanism 1313 which is capable of causing the end portions 141 a and 142 a of the first current path 141 and the second current path 142 of at least one of the power-supplying coils 111 and 112 to be short-circuited with each other. The power-supplying coil short-circuit mechanism 1313 is arranged to cause a variable current of the oscillator 1312 to flow in the power-supplying coils 111, 112, and 113 and stops the supply of the variable current to the power-supplying coil 111, 112, or 113 at the same time as that coil is short-circuited. The power-supplying coil short-circuit mechanism 1313 therefore has a function of switching the short-circuit of the power-supplying coils 111, 112, and 113 and a function as a current path switcher (output target switching mechanism) of switching the output target of the variable current of the oscillator 1312.

The magnetic field formation device 101 structured as above is able to cause at least one of the power-supplying coils 111, 112, and 113 to function as a power supplying resonator and change the distribution of the magnetic field strength of a variable magnetic field by sending a magnetic field to the power supplying resonator at a different angle. Furthermore, as the switching is repeated, a variable magnetic field with magnetic field strength which is uniformized in a variation amount can be formed at the predetermined region A. Furthermore, as at least one of the power-supplying coils 111, 112, and 113 functioning as a power supplying resonator resonates, the magnetic field strength of the variable magnetic field at the predetermined region A is enhanced.

(Magnetic Field Formation Device: Oscillation Controller: Oscillator)

The oscillator 1312 is configured to receive a current outputted from the power source PS and is capable to outputting a variable current with any oscillating frequency. The oscillating frequency of the oscillator 1312 is preferably changeable to allow for the use of various types of magnetic field formation devices 101. Furthermore, each of the oscillating frequency, the voltage, and the current of the oscillator 1312 may be changeable in accordance with the specification of the power-supplying coil 111, 112, or 113 which is the output target.

While in the present embodiment the oscillator 1312 is indirectly short-circuited with the power-supplying coils 111, 112, and 113 via the power-supplying coil short-circuit mechanism 1313, the disclosure is not limited to this arrangement and the oscillator 1312 may be directly short-circuited to the power-supplying coils 111, 112, and 113. In this case, the variable current from the oscillator 1312 can be supplied to all power-supplying coils 111, 112, and 113. Alternatively, the power-supplying coil short-circuit mechanism 1313 may be connected to the power source PS and the oscillator 1312 may be provided on each of current paths connecting the power-supplying coil short-circuit mechanism 1313 with the respective power-supplying coils 111, 112, and 113. In this case, the power-supplying coil short-circuit mechanism 1313 is able to switch the power-supplying coil which is the output target of the variable current, by switching the output target of the current output from the power source PS between the three oscillators 1312 on the respective current paths.

(Magnetic Field Formation Device: Oscillation Controller: Power-Supplying Coil Short-Circuit Mechanism)

As shown in FIG. 12, the power-supplying coil short-circuit mechanism 1313 includes: a switch mechanism which is configured to switchably output a variable current from the oscillator 1312 to each of the power-supplying coils 111, 112, and 113; and a short-circuit mechanism which is able to cause the end portions 141 a and 142 a of the first current path 141 and the second current path 142 of each of the power-supplying coils 111, 112, and 113 to short-circuit with each other.

The switch mechanism includes plural switches. Each of these switches is switchable between connection (on-state) and disconnection (off-state) of an input end and an output end. The input ends of all switches are connected to the oscillator 1312. Meanwhile, each output end is connectable to one of the end portions 141 a and 142 a of the first current path 141 and the second current path 142 of the power-supplying coils 111, 112, and 113 via a switch of the short-circuit mechanism. With this arrangement, the switch mechanism supplies a variable current from the oscillator 1312 to only one of the power-supplying coils 111, 112, and 113, which is connected to a switch in the on-state.

The short-circuit mechanism includes switches which correspond to the respective power-supplying coils 111, 112, and 113. Each of these switches is able to switch between short-circuit (on-state) and disconnection (off-state) between a first terminal and a second terminal. The first terminal of each switch is connected to the end portion 141 a of the first current path 141 of each of the power-supplying coils 111, 112, and 113. The second terminal of each switch is connected to the end portion 142 a of the second current path 142 of each of the power-supplying coils 111, 112, and 113. With this arrangement, the switches of the short-circuit mechanism are able to cause the end portions 141 a and 142 a of the first current path 141 and the second current path 142 of each of the power-supplying coils 111, 112, and 113 to be short-circuited or disconnected, by switching the first terminal and the second terminal between short-circuited (on-state) and disconnected (off-state). While in the present embodiment the end portions 141 a and 142 a of the first current path 141 and the second current path 142 are short-circuited by the short-circuit mechanism, the disclosure is not limited to this arrangement. The end portions 141 a and 142 a may be connected to the GND to be short-circuited.

The switches of the above-described short-circuit mechanism are arranged to operate in sync with the switch mechanism. To be more specific, the switch mechanism stops the output of a variable current from the oscillator 1312 to the power-supplying coils 111, 112, and 113 for which the end portions 141 a and 142 a of the first current path 141 and the second current path 142 are short-circuited by a switch of the short-circuit mechanism, whereas the switch mechanism outputs the variable current from the oscillator 1312 to the power-supplying coils 111, 112, and 113 for which the end portions 141 a and 142 a of the first current path 141 and the second current path 142 are disconnected.

The power-supplying coil short-circuit mechanism 1313 includes a short-circuit control mechanism. The short-circuit control mechanism is able to switch each switch between the on-state and the off-state. For example, there are: a short-circuit pattern 1 in which the end portions 141 a and 142 a of the first current path 141 and the second current path 142 of the power-supplying coil 111 are short-circuited; a short-circuit pattern 2 in which the end portions 141 a and 142 a of the power-supplying coil 112 are short-circuited; a short-circuit pattern 3 in which the end portions 141 a and 142 a of the power-supplying coil 113 are short-circuited; a short-circuit pattern 4 in which the end portions 141 a and 142 a of the power-supplying coils 111 and 112 are short-circuited; a short-circuit pattern 5 in which the end portions 141 a and 142 a of the power-supplying coils 112 and 113 are short-circuited; and a short-circuit pattern 6 in which the end portions 141 a and 142 a of the power-supplying coils 111 and 113 are short-circuited. The short-circuit control mechanism is able to switch a combination selected from these short-circuit patterns 1 to 6 at any timing. As described above, in the present embodiment, there are six output targets as an output target of the variable current from the oscillator 1312, and the output target of the variable current is switchable by the short-circuit control mechanism.

In addition to the above, the short-circuit control mechanism of the power-supplying coil short-circuit mechanism 1313 has a function of executing a process of short-circuiting the end portions 141 a and 142 a with a predetermined combination of a timing and a duration. With this arrangement, the short-circuit control mechanism is able to easily generate a variable magnetic field with predetermined magnetic field strength in consideration of heat generation and power consumption, by adjusting the timing and duration of the connection process.

To be more specific, the short-circuit control mechanism is able to select one of plural short-circuit times (time 1 to time n), and a suitable short-circuit time is selected in consideration of the use and state of the magnetic field formation device 101. The short-circuit control mechanism is able to determine a timing to execute the short-circuit operation between the end portions 141 a and 142 a, by means of plural short-circuit patterns. To be more specific, there are “every 1 pattern” with which the short-circuit operation is executed each time one of the short-circuit patterns 1 to 6 is completed, “every 2 patterns” with which the short-circuit operation is executed each time two of the short-circuit patterns 1 to 6 are completed, and so on. As one of these options is selected, various short-circuit operations are executable at a desired timing.

(Magnetic Field Formation Device: Modification of Oscillation Controller: Power-Supplying Coil Short-Circuit Mechanism and Current Path Switcher)

While in the oscillation controller 131 above the power-supplying coil short-circuit mechanism 1313 executes a part of the function of the current path switcher, the disclosure is not limited to this arrangement. As shown in FIG. 13, a power-supplying coil short-circuit mechanism 1313A and a current path switcher 1311 may be independently provided. Control is easily done in this case, because control for short-circuiting is separated from control for current switching.

To be more specific, the oscillation controller 131 includes the power-supplying coil short-circuit mechanism 1313A including only the short-circuit mechanism, the oscillator 1312, and the current path switcher 1311 which performs switching to supply the variable current of the oscillator 1312 to at least one of and not all of the power-supplying coils 111, 112, and 113.

(Magnetic Field Formation Device: Oscillation Controller: Current Path Switcher)

The current path switcher 1311 includes a switch mechanism which is configured to switchably output the variable current of the oscillator 1312 to each of the power-supplying coils 111, 112, and 113. The switch mechanism includes plural switches. Each of these switches is switchable between connection (on-state) and disconnection (off-state) of an input end and an output end. The input ends of all switches are connected to the oscillator 1312. Meanwhile, the output ends are connected to the respective power-supplying coils 111, 112, and 113. With this arrangement, the switch mechanism supplies a variable current from the oscillator 1312 to only one of the power-supplying coils 111, 112, and 113, which is connected to a switch in the on-state.

As shown in FIG. 14, the current path switcher 1311 includes a switch control mechanism. The switch control mechanism is able to switch each switch of the switch mechanism between the on-state and the off-state. For example, provided that a route through which the variable current is supplied to the power-supplying coil 111 is a route A, a route through which the variable current is supplied to the power-supplying coil 112 is a route B, and a route through which the variable current is supplied to the power-supplying coil 113 is a route C, there are six connection patterns 1 to 6.

To be more specific, there are (1) a connection pattern 1 with which the variable current is supplied only to the power-supplying coil 111 by using only the route A; (2) a connection pattern 2 with which the variable current is supplied only to the power-supplying coil 112 by using only the route B; (3) a connection pattern 3 with which the variable current is supplied only to the power-supplying coil 113 by using only the route C; (4) a connection pattern 4 with which the variable current is supplied to the power-supplying coils 111 and 112 by using the route A and the route B; (5) a connection pattern 5 with which the variable current is supplied to the power-supplying coils 112 and 113 by using the route B and the route C; and (6) a connection pattern 6 with which the variable current is supplied to the power-supplying coils 111 and 113 by using the route A and the route C. The switch control mechanism is able to switch a combination selected from these connection patterns 1 to 6 at any timing.

In addition to the above, the switch control mechanism of the current path switcher 1311 has a function of executing a stop process of not supplying the variable current to any of the power-supplying coils 111, 112, and 113, with a predetermined combination of a timing and a duration. With this arrangement, the switch control mechanism is able to easily generate a variable magnetic field with predetermined magnetic field strength in consideration of heat generation and power consumption, by adjusting the timing and duration of the stop process.

To be more specific, the switch control mechanism is able to perform a pause operation (stop process) of stopping the power supply to all of the power-supplying coils 111, 112, and 113 by turning off all switches of the switch mechanism. In the pause operation, a pause time is selectable from plural pause times (time 1 to time n), and a suitable pause time is selected in consideration of the use and state of the magnetic field formation device 101.

In addition to the above, the switch control mechanism is able to determine a timing to execute the pause operation based on plural pause patterns. To be more specific, there are “every 1 pattern” with which the pause operation is executed each time one of the connection patterns 1 to 6 is completed, “every 2 patterns” with which the pause operation is executed each time two of the connection patterns 1 to 6 are completed, and so on. As one of these options is selected, various pause operations are executable at a desired timing.

For example, the current path switcher 1311 is able to perform a powering operation in which a route A connection state with the connection pattern 1, the pause operation, a route B connection state with the connection pattern 2, the pause operation, a route C connection state with the connection pattern 3, and the pause operation are repeated in order. Furthermore, for example, the current path switcher 1311 is able to perform a powering operation in which the route A connection state with the connection pattern 1, the route B connection state with the connection pattern 2, the route C connection state with the connection pattern 3, and the pause operation are repeated in order.

The current path switcher 1311 may be constituted by a circuit having a programmability such as a microcomputer and an operation of switching the variable current may executed by software, or may be constituted by a combination of ICs and the switching operation may be executed by hardware.

(Application Example of Magnetic Field Formation Device)

The following will describe a case where the magnetic field formation device 101 structured as above is used in a power-supplying device as shown in FIG. 15. To put it differently, the following will describe a case where the magnetic field formation device 101 is mounted on the charger 7 as a power-supplying device and electric power is supplied in a wireless manner to the power-receiving module 9 which is a power-receiving device of the driving device 5 provided in the charger 7.

The charger 7 (power-supplying device) on which the magnetic field formation device 101 is mounted and the driving device 5 (secondary battery 10, power-receiving module 9) constitute a power receiving/supplying device 1 or a power receiving/supplying system. To put it differently, the power receiving/supplying device 1 includes the driving device 5 including the power-receiving coil mechanism 2 receiving power by a magnetic field and the charger 7 supplying power to the driving device 5 by wireless transmission.

In the power receiving/supplying device 1, the charger 7 and the driving device 5 may be treated in combination. While the description below deals with a case where the power-receiving coil mechanism 2 receives power by magnetic field resonance, the disclosure is not limited to this arrangement and it may receive power by electromagnetic induction.

(Application Example of Magnetic Field Formation Device: Charger and Housing Cup)

The charger 7 includes the housing cup 6 in which the driving device 5 such as a mobile device including a power-receiving device is mounted and the magnetic field formation device 101 which is configured to generate a variable magnetic field at the housing region B of the housing cup 6 to allow the power-receiving module 9 to receive power irrespective of the direction and position of the power-receiving module 9. The housing cup 6 may be arranged such that plural driving devices 5 are simultaneously placed at the housing region B. To put it differently, the housing region B of the housing cup 6 may have a capacity capable of simultaneously storing plural driving devices 5.

The magnetic field formation device 101 is provided in a casing of the charging case 60 in which the housing cup 6 is provided. When the magnetic field formation device 101 is employed in the charger 7, any of the power-supplying coils 111, 112, and 113 functions as a power feeding coil 31 whereas the remaining power-supplying coils 111, 112, and 113 function as a power-supplying resonator. A power-supplying coil mechanism 3 including the power feeding coil 31 is connected to an oscillation control circuit 81 which is an IC chip in which the oscillation controller 131 outputting a variable current is embodied.

The oscillation control circuit 81 and the power-supplying coil mechanism 3 are combined as a power-supplying module 8 in order to improve the handleability. The oscillation control circuit 81 is connected to a USB terminal 61. The USB terminal 61 is connectable to an unillustrated USB cable of an external device such as a personal computer provided outside the charger 7, so that 5V DC power can be supplied from the external device to the oscillation control circuit 81. Instead of the USB terminal 61, the charger 7 may be connected to a home AC power cord, and DC power converted from AC power by a rectifying circuit or a converter may be suppliable to the oscillation control circuit 81.

(Application Example of Magnetic Field Formation Device: Driving Device)

An example of the driving device 5 charged and driven by the above-described charger 7 is a mobile device. The mobile device encompasses a handheld device which can be carried on a hand and a human-wearable device which can be worn a human body. Specific examples of the mobile device include a portable computer (a laptop PC, a note PC, a tablet PC, or the like), a headset, a camera, an audio visual device (a portable music player, an IC recorder, a portable DVD player, or the like), a calculator (such as a pocket computer and an electronic calculator), a game console, a computer peripheral (a portable printer, a portable scanner, a portable modem, or the like), a dedicated information device (an electronic dictionary, an electronic notebook, an electronic book, a portable data terminal, or the like), a portable communication terminal, a voice communication terminal (a portable phone, a PHS, a satellite phone, a third party radio system, an amateur radio, a specified low power radio, a personal radio, a citizen radio, or the like), a data communication terminal (a portable phone, a PHS (a feature phone and a smart phone), a pager, or the like), a broadcasting receiver (a television receiver and a radio), a portable radio, a portable television receiver, a one-seg receiver, another type of device (a wristwatch and a pocket watch), a hearing aid, a handheld GPS, a security buzzer, a flashlight/pen light, a battery pack, and the like. Examples of the above hearing aid include an ear-hook hearing aid, an ear hole fitting hearing aid, and a glasses-type hearing aid. The driving device 5 may be a desktop device such as a personal computer.

(Application Example of Magnetic Field Formation Device: Driving Device: Power-Receiving Coil Mechanism)

The driving device 5 includes the power-receiving coil mechanism 2 which is configured to receive power by a magnetic field. In addition to the power-receiving coil mechanism 2, the driving device 5 includes: a power control circuit 91 to which power is supplied from the power-receiving coil mechanism 2; and a magnetic member 4. The power-receiving coil mechanism 2, the power control circuit 91, and the magnetic member 4 are integrated as a power-receiving module 9. The power-receiving module 9 is connected to a secondary battery 10.

The power-receiving coil mechanism 2 is configured to receive power in such a way that magnetic field resonance is caused by a variable magnetic field in the housing region B (predetermined region A). To be more specific, the power-receiving coil mechanism 2 includes a power-receiving coil 21 and a power-receiving resonator 22 provided on the inner circumferential side of the power-receiving coil 21. The “magnetic field resonance” indicates a resonance phenomenon of synchronization at a resonance frequency of a variable magnetic field. Examples of the types of coils used in the power-receiving coil 21 and the power-receiving resonator 22 include: a spiral type, a solenoid type, and a loop type. In regard to the positional relation between the power-receiving coil 21 and the power-receiving resonator 22, the power-receiving coil 21 may be provided on the inner circumferential side or the outer circumference side of the power-receiving resonator 22, or the power-receiving coil 21 and the power-receiving resonator 22 may be provided not to overlap each other in the radial direction.

The driving device 5 includes the magnetic member 4 provided at the power-receiving coil mechanism 2. The magnetic member 4 increases the magnetic field strength by increasing the mutual inductance of the power-receiving coil mechanism 2 and increasing the magnetic flux density. As the magnetic field strength of the power-receiving coil mechanism 2 is increased by the magnetic member 4, the charging characteristic is maintained to be high in the power-receiving coil mechanism 2, and power at least at a desired level is receivable with an improved degree of freedom in the layout of the power-receiving coil mechanism 2. The power-receiving coil mechanism 2 preferably includes the magnetic member 4 but may not include the magnetic member 4.

The magnetic member 4 is provided on the inner circumferential side of the power-receiving coil mechanism 2. While the positional relation between the power-receiving coil mechanism 2 and the magnetic member 4 in the axial direction, i.e., the positional relation when viewed in the direction orthogonal to the axial direction is not particularly limited, these members are preferably provided so that the power-receiving coil mechanism 2 is provided at an intermediate portion between one end side and the other end side of the magnetic member 4. This “intermediate portion” between one end side and the other end side of the magnetic member 4 indicates a part of a region sandwiched between the one end and the other end, excluding the one end and the other end.

The positional relation between the power-receiving coil mechanism 2 and the magnetic member 4 in the axial direction is further preferably arranged so that the power-receiving coil mechanism 2 is provided at a central portion between one end side and the other end side of the magnetic member 4. The positional relation between the power-receiving coil mechanism 2 and the magnetic member 4 in the axial direction is preferably arranged such that the charging characteristic of the magnetic member 4 is not significantly different between a case where the coil surface 2 a of the power-receiving coil mechanism 2 on one side faces a magnetic field generating surface 3 a of the power-supplying coil mechanism 3 and a case where the coil surface 2 b of the power-receiving coil mechanism 2 on the other side faces the magnetic field generating surface 3 a.

The power-receiving resonator 22 of the power-receiving coil mechanism 2 is provided so that the power-receiving coil 21 is disposed on the outer circumference side. To be more specific, the power-receiving coil mechanism 2 is arranged such that the power-receiving resonator 22 is provided between the power-receiving coil 21 on the outermost circumferential side and the magnetic member 4 on the innermost circumferential side. While the positional relation between the power-receiving resonator 22 and the power-receiving coil 21 in the axial direction is not particularly limited, these members are preferably provided so that the power-receiving coil 21 is provided at an intermediate portion between one end side and the other end side of the power-receiving resonator 22. The positional relation between the power-receiving resonator 22 and the power-receiving coil 21 in the axial direction is further preferably arranged so that the power-receiving coil 21 is provided at a central portion between one end side and the other end side of the power-receiving resonator 22.

The magnetic member 4 is made of resin in which magnetic powder is dispersed. The resin used for the magnetic member 4 may be thermosetting resin or thermoplastic resin, and is not particularly limited. Examples of the thermosetting resin include epoxy resin, phenol resin, melamine resin, vinyl ester resin, cyano ester resin, maleimide resin, and silicon resin. Examples of the thermoplastic resin include acrylic resin, vinyl acetate based resin, and poly vinyl alcohol based resin. The present example adopts a resin whose main component is epoxy resin.

Further, soft magnetic powder is used as the magnetic powder dispersed in the resin. Examples of the soft magnetic powder include pure Fe, Fe—Si, Fe—Al—Si (sendust), Fe—Ni (permalloy), soft ferrites, Fe-base amorphous, Co-base amorphous, and Fe—Co (permendur); however, is not particularly limited. The shape of the magnetic member 4 is suitably determined, too.

(Application Example of Power Receiving/Supplying Device 1: Driving Device: Power Control Circuit)

The power control circuit 91 is mounted on a circuit substrate.

As shown in FIG. 16, the power control circuit 91 has a function of controlling the charging of the secondary battery 10. The power control circuit 91 may be a circuit further having a function of controlling the discharging.

To be more specific, the power control circuit 91 includes a rectification stabilization unit 911 which is configured to output DC power by rectifying AC power supplied from the outside via the power-receiving coil mechanism 2 outputting the DC power, a charging unit 912 configured to supply the DC power outputted from the rectification stabilization unit 911 to the secondary battery 10 at a charging voltage, and a transformation unit 913 configured to execute a signal process. The transformation unit 913 is connected to a driving mechanism 11 which is driven by the charged power of the secondary battery 10.

The rectification stabilization unit 911 is a rectification-stabilization IC, for example. The rectification-stabilization IC is an IC in which functions such as full bridge synchronous rectification, voltage conditioning and wireless power control, and protection from a voltage, current, or temperature anomaly are integrated into one chip. The rectification stabilization unit 911 may not be provided when the power outputted from the power-receiving coil mechanism 2 is DC power.

The charging unit 912 is an IC (charging circuit) for a constant current/constant voltage linear charger, and has functions such as a function of notifying that the charging current has been reduced to a predetermined setting value, a function of ending the charging using a timer, a function of stabilizing the charging current by means of thermal feedback, and a function of limiting the chip temperature in a high-power mode or in high ambient temperatures.

The transformation unit 913 is a transformer circuit which functions as a transformation unit performing signal processing of converting the charged power of the secondary battery 10 to the driving power for the driving mechanism 11 and outputting the converted power. As the transformation unit 913, a linear regulator may be employed for voltage dropping, or a switching regulator or a charge pump may be employed for voltage boosting and voltage dropping. An example of each regulator is one adopting a semiconductor elements so the current is switched on and off at a high speed.

(Application Example of Power Receiving/Supplying Device 1: Driving Device: Power Control Circuit with High-Capacitance Capacitor)

As shown in FIG. 17 and FIG. 18, the power control circuit 91 may include a high-capacitance capacitor as a first-stage power storage unit 920. The first-stage power storage unit 920 has a capacity of discharging at a voltage equal to or higher than the minimum operating voltage of an electric part on a subsequent stage, and is preferably provided in cases where a received voltage varies. The “electric part” encompasses not only a secondary battery and an electronic circuit substrate but also all driving devices driven by supplied power. The “minimum operating voltage” indicates the minimum voltage with which an electric part is properly driven. For example, the minimum operating voltage of a secondary battery is the minimum voltage with which a charging IC of the secondary battery is properly driven.

The first-stage power storage unit 920 is particularly preferable when switching of conduction to the power feeding coil 31 is performed by the power-supplying coil short-circuit mechanism 1313 or the current path switcher 1311. To be more specific, the driving device 5 (power-receiving device) including the power control circuit 91 may be configured to receive power by a variable magnetic field generated at the predetermined region A by the magnetic field formation device 101, and may include: the power-receiving coil mechanism 2 (power-receiving mechanism) configured to receive power by the variable magnetic field; and the first-stage power storage unit 920 (high-capacitance capacitor) having a capacity of being charged by a current received by the power-receiving coil mechanism 2 and discharging at least at the minimum operating voltage of the secondary battery 10, etc. (electric part) on a subsequent stage while the current path switcher 1311 is performing the switching of the output target.

The driving device 5 may include: the power-receiving coil mechanism 2 (power-receiving device) configured to receive power by a variable magnetic field; and a capacitor having a capacity of being charged by a current received by the power-receiving coil mechanism 2 and discharging at least at the minimum operating voltage of the secondary battery 10, etc. (electric part) on a subsequent stage while the current path switcher 1311 is performing the stop process.

According to the arrangement above, even when an induced current cannot be obtained from the power-receiving coil mechanism 2 on account of the switching process or the stop process performed for the power feeding coil 31, the charging unit 912 or the like is stably driven because the first-stage power storage unit 920 performs the discharge at least at the minimum operating voltage of the charging unit 912 or the like.

The first-stage power storage unit 920 (high-capacitance capacitor) may have a capacity of discharging at least at the minimum operating voltage of an electric part on a subsequent stage during the stop process in which the current path switcher 1311 does not supply a variable current to the power feeding coil 31 (power-supplying coil), in addition to the period during which the switching of the output target is being performed by the power-supplying coil short-circuit mechanism 1313 or the current path switcher 1311. According to this arrangement, in addition to the period during which the switching of the output target is being performed by the current path switcher 1311, even when an induced current cannot be obtained from a power-receiving coil due to the stop process for the power-supplying coil and the power supplying resonator, the electric part is stably driven as the first-stage power storage unit 920 performs the discharge at least at the minimum operating voltage of the electric part.

(Application Example of Power Receiving/Supplying Device: Driving Mechanism: Driving Device)

Examples of the driving mechanism 11 include a mechanism in which a component converting electric power to kinetic energy such as a speaker and a motor is incorporated, a light emitting mechanism or an illumination mechanism in which a component converting electric power to optical energy such as an LED light source and a laser light source is incorporated, and a microcomputer. Apart from these mechanisms, any types of mechanism driven by electric power may be used as the driving mechanism 11. The power-receiving coil mechanism 2 is configured to correspond to wireless power supply with which power supply is carried out in a mechanically contactless state. Examples of the wireless power supply include electromagnetic induction and magnetic field resonance (magnetic resonance).

(Application Example of Power Receiving/Supplying Device: Driving Device: Secondary Battery)

As the secondary battery 10, any type of batteries which are chargeable and rechargeable can be used. Examples of the secondary battery 10 include a lead storage battery, a valve-regulated lead storage battery, a lithium ion battery, a lithium ion polymer battery, a lithium iron phosphate ion battery, a lithium-sulfur battery, a lithium titanate battery, a nickel-cadmium storage battery, a nickel-hydrogen rechargeable battery, a nickel-iron battery, a nickel-lithium battery, a nickel-zinc battery, a rechargeable alkali battery, a sodium-sulfur battery, a redox flow battery, a zinc-bromine flow battery, a silicon battery, and a Silver-Zinc battery.

Although the above descriptions have been provided with regard to the characteristic parts so as to understand the invention more easily, the invention is not limited to the embodiment as described above and can be applied to the other embodiments and the applicable scope should be construed as broadly as possible. Furthermore, the terms and phraseology used in the specification have been used to correctly illustrate the present invention, not to limit it. In addition, it will be understood by those skilled in the art that the other structures, systems, methods and the like included in the spirit of the present invention can be easily derived from the spirit of the invention described in the specification. Accordingly, it should be considered that the present invention covers equivalent structures thereof without departing from the spirit and scope of the invention as defined in the following claims. In addition, it is required to sufficiently refer to the documents that have been already disclosed, so as to fully understand the objects and effects of the present invention.

REFERENCE SIGNS LIST

1 power receiving/supplying device

2 power-receiving coil mechanism

3 power-supplying coil mechanism

4 magnetic member

5 driving device

6 housing cup

7 charger

8 power-supplying module

9 power-receiving module

10 secondary battery

21 power-receiving coil

22 power-receiving resonator

31 power feeding coil

111 power-supplying coil

112 power-supplying coil

131 oscillation controller

1111 power supplying sub coil

1112 power supplying sub coil

1311 current path switcher

1312 oscillator

A predetermined region

B housing region 

The invention claimed is:
 1. A magnetic field formation device configured to generate a variable magnetic field at a predetermined region, comprising: power-supplying coils each of which generates a variable magnetic field by receiving a variable current via a first current path on one coil end side and a second current path on the other coil end side; a resonance capacitor which is provided on at least one of the first current path and the second current path of each power-supplying coil; a power-supplying coil short-circuit mechanism which short-circuits end portions of the first current path and the second current path of at least one of the power-supplying coils to cause it to function as a power supplying resonator; and an output target switching mechanism which is configured to output a variable current to one of output targets which are at least one of and not all of the power-supplying coils and is configured to repeatedly switch the output target to which the variable current is output, wherein all of the power-supplying coils are disposed so that their coil surfaces face the predetermined region, and the at least one of the power-supplying coils that functions as the power supplying resonator is disposed to have a coil surface direction which intersects with a coil surface direction of another of the power-supplying coils.
 2. The magnetic field formation device according to claim 1, which is configured to generate a variable magnetic field at a predetermined region, wherein, all of the power-supplying coils are disposed so that coil surfaces oppose the predetermined region, and at least one of the power-supplying coils is disposed to have a coil surface direction which is parallel to coil surface directions of the other power-supplying coils.
 3. The magnetic field formation device according to claim 1, wherein, the output target switching mechanism executes a stop process of not outputting the variable current to any of the power-supplying coils, with a predetermined combination of a timing and a duration.
 4. A power-supplying device comprising the magnetic field formation device according to claim
 1. 5. A power-receiving device comprising a power-receiving mechanism which is configured to receive power by a variable magnetic field generated at a predetermined region by the magnetic field formation device according to claim
 1. 6. A power-receiving device configured to receive power by a variable magnetic field generated at a predetermined region by the magnetic field formation device according to claim 2, comprising: a power-receiving mechanism configured to receive power by the variable magnetic field; and a high-capacitance capacitor which has a capacity of being charged by a current received by the power-receiving mechanism and discharging at least at a minimum operating voltage of an electric part on a subsequent stage while an output target of the variable current by the current output controller is being switched.
 7. The power-receiving device according to claim 6, wherein, the high-capacitance capacitor has a capacity of discharging at least at the minimum operating voltage of the electric part on the subsequent stage during a stop process in which the output target switching mechanism does not supply the variable current to any of the power-supplying coil.
 8. A power receiving/supplying device comprising: a power-supplying device including the magnetic field formation device according to claim 1; and a power-receiving device including a power-receiving mechanism which is configured to receive power by the variable magnetic field generated by the power-supplying device.
 9. A mobile device comprising a power-receiving mechanism which is configured to receive power by a variable magnetic field generated at a predetermined region by the magnetic field formation device according to claim
 1. 10. A coil device configured to generate a variable magnetic field at a predetermined region, comprising: a plurality of coils; a variable current supplying mechanism configured to supply a variable current to each of the coils via a first current path on one coil end side and a second current path on the other coil end side of each coil; a resonance capacitor which is provided on at least one of the first current path and the second current path of each coil; and a coil short-circuit mechanism which short-circuits end portions of the first current path and the second current path of at least one of the coils to cause it to function as a power supplying resonator, wherein all of the coils are disposed so that their coil surfaces face the predetermined region, and the at least one coil that functions as the power supplying resonator is disposed to have a coil surface direction which intersects with a coil surface direction of another of the coils.
 11. A method of generating a variable magnetic field at a predetermined region, comprising: providing a plurality of coils with coil surfaces facing the predetermined region; generating a variable magnetic field by supplying a variable current via a first current path on one coil end side and a second current path on the other coil end side of each coil; providing a resonance capacitor on at least one of the first current path and the second current path of each coil; and switching at least one of the coils to a power supplying resonator by short-circuiting end portions of its first current path and second current path, wherein the power supplying resonator is disposed to have a coil surface direction which intersects with a coil surface direction of another of the plurality of coils. 